RPG Design: Core Mechanic

新年快乐! (Happy Chinese New Year!)

This week, I wanted to talk about one of the most important parts of a tabletop RPG's design: the Core Mechanic.  By "Core Mechanic," I mean rules covering general task resolution (e.g., combat, investigation, negotiation, etc.) and reactions (e.g., surprise, morale, etc.), rather than related sub-systems (e.g., damage, initiative, etc.) or unrelated sub-systems (e.g., advancement, encumbrance, etc.).

Not a core mechanic

Any discussion of Core Mechanics should begin with the ur-RPG, Original Dungeons & Dragons (1974).  OD&D uses d20 target number roll under to determine hits in combat (the "Alternative Combat System" aka THAC0) and a collection of rules for reactions, such as d20 target number roll under (Saving Throws), d6 target number roll under (Surprise) and 2d6 look up (Monster Reactions).  Additionally, as mentioned before, there are simply no rules for large areas of task resolution, with each table addressing this situation in their own way through house rules and/or role-play (for some, this is a feature rather than a bug).

These gaps, however, begin to be filled in with Supplement I: Greyhawk (Thieves Skills use d100 target number roll under and d6 target number roll under, Open Doors uses d6 target number roll under) and by AD&D, include many wonky rules, such as Chance to Know Spell.

Having so many disparate rules is a drag, both figuratively and literally, since they consume large amounts of the DM's bandwidth and/or slow down the game with multiple look up charts.

Unsurprisingly, while D&D was becoming more complex, a number of other Old School RPGs chose the opposite approach with more streamlined rule sets, such as Traveller (1977, mostly 2d6 target number roll over) and RuneQuest (1978, mostly d100 target number roll under).  This more simplified design approach has won out, with most New School RPGs employing a universal Core Mechanic, most notably 3e and newer D&D (d20 target number roll over).

I've spent a fair bit of time grumbling about various aspects of New School RPGs, but this is one area that I feel is a definite improvement than back in the Ye Goode Olde Days.  By streamlining the Core Mechanic (and often other parts of the rules set as well),  gameplay speeds up and GMs can focus on more rewarding parts of the game.

...and we liked it!

For Sorcery & Steel, my rules set, I've adopted a universal Core Mechanic (d20 target number roll under) to steamline play while not stepping too far away from its Old School D&D roots (descending AC).  While starting as a set of AD&D house rules, Sorcery & Steel has become its own thing.  However, I want to keep its DNA recognizable while fulfilling my other design goals.

Literature Review: "Beyond the Black River" (1935)

This week, in honor of R.E. Howard's birthday on January 22nd, I wanted to discuss one of my favorite Swords & Sorcery yarns, the classic Conan the Barbarian tale "Beyond the Black River":

Although a ripping Sword & Sorcery tale (with gory action, savage imagery and fell magic), "Beyond the Black River" is also unusual and noteworthy for a Conan story in a number of ways.

Firstly, the viewpoint character for much of this tale is a young man named Balthus (likely the author's self-insert) who has travelled to the very edge of the civilized world to seek his fortune rather than everyone's favorite Cimmerian murder machine.  This allows us to see Conan from a somewhat different perspective.  Anyway, unfortunately, this is the worst possible time to visit Conajohara, the newest province of the Kingdom of Aquilonia carved out of the lands of the Picts, since an irate sorcerer named Zogar Sag is uniting thousands of Pictish warriors to wreak bloody vengeance!

Taking along his new sidekick, Conan discusses the rapidly deteriorating situation with Governor Valannus, and Valannus decides their own hope is to find the sorcerer in the jungle beyond the Black River and terminate him with extreme prejudice.  Accompanied by a dozen handpicked rangers, Conan and Balthus head off on their kill mission into the heart of darkness to prevent an apocalypse now.

As in Francis Ford Coppola's acclaimed retelling of Joseph Conrad's acclaimed novella, the plan quickly goes off the rails for Conan and Co, and young Balthus finds himself fighting for his life!

Much death and mayhem ensues.

“Civilization is unnatural. It is the whim of circumstance. And barbarism must ultimately triumph.”

One of the major themes of Conan's tales, the struggle between civilization and barbarism, is front and center in "Beyond the Black River."  Indeed, it drives the action since the two are in actual direct conflict.  However, there's a philosophical level as well: This is an unusually moody and reflective Conan story and the normally taciturn barbarian waxes at length about on the topic.    

For example, in his opinion, this latest Aquilonian land grab is dangerous and foolhearty and the barbarian explains to Balthus, "you Hyborians have expanded as far as you'll be allowed to expand."  There are signs of impending disaster, just like Aquilonia's last attempt to colonize barbarian lands, the southern marches of Cimmerian.

In another unusual move, Conan also reveals something of his past, that he was one of the reavers that sacked the fort-town Venarium, even though he hadn't reached 15 winters.  Testosterone practically oozes from the pages.

Another interesting point about "Beyond the Black River" is how much it resembles tale of the Old West, another great love of Messr Howard.  In fact, remove sorcerer Zogar Sag and the other supernatural elements and this story reads much like Howard's westerns, with the Picts standing in for Native Americans.

All in all, "Beyond the Black River" is one of Messr Howard's finest works, filled with both classic pulp action and melancholy philosophical ruminations.  It provides arguably the clearest picture of Conan, both in thought and in action.   Every fan of Swords & Sorcery should take a look!

RPG Design: Gear

Two weeks ago, I discussed the tracking of a PC's gear and any resulting effects (Encumbrance), and this week, I wanted to followup and talk about gear itself in tabletop RPGs.

Gear is, unsurprisingly, a key part of many tabletop RPGs.  I've always enjoyed the mini-game of kitting out a PC.  It's an early opportunity to place your stamp on a PC.  Even when there isn't a mechanical difference between various types of equipment, choices can convey a different feel for roleplaying purposes, such as wielding an axe versus a sword.

Attribution: Dewfooter

Some games also expect that a not inconsiderable portion of a PC's power comes from their equipment.  For example, in Original Dungeons & Dragons, a game where a single hit from any weapon can kill any 1st level character except a Fighting Man who rolled max hit points, an often early priority for the party is getting their frontline into plate armor, which greatly increases survivability.

However, equipment is also important not only because of its actual utility during the game, but also because it can be an important part of shaping your character and your play style.

In newer editions of D&D, as well as other designs, have altered this assumption by placing an increased emphasis on a PC's internal power (e.g., feats, prestige classes, etc.), leading to a lesser role for gear.  This, in turn, led to more advanced planning and character design for these PCs (e.g., feat chains, feat combos, etc.), sometimes many levels in advance.

On the other hand, in the Old School play style, story is usually emergent in response to actual play, rather subject to advanced planning, and discovery of new gear is no exception.  An interesting example of this is one of my favorite RPG stories, "Gimli of Arabia": a dwarf fighter in a 1e AD&D game happens across a +3 scimitar during a desert adventure.  He decides to use the powerful weapon despite not being proficient or optimized for such and unexpectedly ends up "going native."

Khazm was an otherwise bog-standard fighter, but adopting an atypical weapon and unusual cultural trappings for his race made him effectively unique in the game-world - this was the days before every demihuman race had an ice subrace and a sea subrace and a desert subrace and a jungle subrace, of course. It didn't take class abilities or feats or prestige classes to make him distinctive - the only rules-wise change to Khazm was spending a weapon proficiency slot on the scimitar after he leveled up - but rather I simply roleplayed him in ways, and surrounded him with trappings, which reflected his adopted culture.

What could possibly go wrong?

Equipment is also important as a form of treasure, especially magic equipment.  Even in games such as OD&D, where GP = XP, there's just something immensely satisfying to finding a PC's first magic weapon in a way that no hoard of gold or jewels can match.

In terms of RPG design and selecting what to include for equipment, many games have extensive equipment lists and some even have entire sourcebooks dedicated to gear, such as this classic:

For Sorcery & Steel, my rules set, I prefer not to have enormous lists of various items, which is a step away from its Old School D&D roots.  This is mainly because, as I've mentioned before, I want to keep bookkeeping limited and to streamline game play.  For example, inspired by the Lone Wolf gamebooks, there are a relatively limited number of weapons, just enough to provide reasonable variety.

But no pole arms.

Board Game Review: "Xiangqi (象棋)" (~1200)

This week, I want give a shout out to one of the most venerable and respected board games and war games of all time: "Xiangqi (Chinese: 象棋; pinyin: xiàngqí), also called Chinese chess":

Attribution: Daniel Danzer

Similar to Chess, Xiangqi is a two player board game wherein each player controls an army of 16 pieces of various types and attempts to checkmate the opponent's General, whilst preventing the opponent from doing the same.  The battlefield consists of a 9 x 10 board with a terrain feature, a river in the middle of the board that is impassible to certain pieces, thus dividing your army into offensive and defensive forces.  The other board features are the palaces (or command tents) of the armies (colored in green and red in the photo above), which restrict the movement of the Generals and the Advisors.

Like Chess, in Xiangqi each faces the other from opposite sides of the board but unlike Chess pieces which are placed within the squares, Xiangqi pieces are placed on the intersection of the lines.

Each army, represented as discs with Chinese characters, consists of:

• 1 General (labelled 將 (trad.) / 将 (simp.) on the black side and 帥 (trad.) / 帅 (simp.) on the red side). 
• 2 Advisors (labelled 士 for Black and 仕 for Red).  
• 2 Elephants (labeled 象 for Black and 相 for Red). 
• 2 Horses (labelled 馬 Black and 傌 for Red).
• 2 Chariots (labelled 車 (trad.) / 车 (simp.) for Black and 俥 (trad.) / 车 (simp.) for Red).  The chariot is sometimes called the rook by English-speaking players, since it is functionally identical to the rook in Chess. 
• 2 Cannons (labelled 砲 for Black and 炮 for Red).
• 5 Soldiers (labelled 卒 for Black and 兵 for Red). 

Although Xiangqi developed over a number of centuries, earliest references to the current version of the game come from around 1200 (e.g., a poem by Liu Kechuang (刘克庄), entitled <<象弈一首,呈叶潜仲>>).  Although overall complexity is similar to the Game of Kings, Xiangqi's gameplay and tactics are sometimes similar to Chess (e.g., forks, pins, and skewers are possible) but sometimes different.  For example, while the Horse and the Knight have similar moves (an orthogonal move followed by a diagonal move), it is possible to block a Horse (i.e., unlike the Knight, the Horse cannot leap over a piece).

In addition, unlike Chess, where the armies occupy the back two ranks of the board (and, indeed, one of the goals of the Development phase in Chess is to "bring your army on to the battlefield"), in Xiangqi, your Soldiers and Cannons are already forward deployed into a skirmish line.  This more likely earlier enemy contact, as well as greater long range orthogonal striking power, earlier promotion of Soldiers v. Pawns, and the restricted movement of the General often makes for an faster paced game than Chess.

Attribution: Peter Griffin

One of the most popular games in China and other parts of Asia, Xiangqi has developed a following in many parts of the world.  Like Chess, Xiangqi is an all-ages game that teaches strategy, patience, forethought and resourcefulness.  The rules are fairly easy to learn but the terrain and the different  nature of the various pieces add depth and complexity.  All in all, it's a fun and challenging game enjoyed by millions everyday.

Any fan of board games and war games owes it to themselves to take a look!

RPG Design: Encumbrance

Happy New Year!

This week, I wanted to talk about an interesting, but often poorly handled or ignored, game design decision for tabletop RPGs: Encumbrance.

Ask about my encumbrance score and I'll put you on the 'Naughty' list!

Encumbrance (aka a PC's carrying capacity) has existed in tabletop role-playing games since the beginning of the hobby.  Since resource management was a key element of gameplay for Original Dungeons & Dragons, Encumbrance became another thing to track during a session, along with spells, torches, food, etc.

However, it can be cumbersome (pun intended), to actually calculate the sum of all of a PC's items and THEN calculate derived in-game effects *EVERY* time there's a change in a PC's inventory, Encumbrance is often hand waved away, especially since most players are more interesting in adventuring than bookkeeping.  On the other hand,  ignoring Encumbrance can lead to disbelief breaking situations, even with well-meaning players, where characters are carrying a ridiculous amount of items and, thus, shatter verisimilitude.

Seriously, GM should occasionally make a surprise check of their PCs' inventories.  Sometimes it's literally jaw-dropping.

Nevertheless, when Encumbrance is done well, it can force some interesting decisions or challenges upon players because of changes to character speed, abilities, etc.    I've also mentioned before that I've been fortunate enough to 1e Advanced Dungeons & Dragons  with a GM who runs the game by the book, including Encumbrance.  Enforcing Reaction and Initiative penalties for Encumbrance forces interesting and sometimes tough decisions on a player.  For example, my elven Magic-User/Thief has 18 Dexterity but only 9 Strength.  To avoid Reaction and Initiative penalties (spell books are heavy!), I couldn't carry a full complement of weapons.

Old School!

I've mentioned before that I've become increasingly lazy as a GM over time.  One way that this trend has influenced the design of my rules set, Sorcery & Steel, is that I've endeavored to remove as much accounting from the system as possible.  This is in line with one of my stated design goals, simplicity.  However, too much simplicity in a rules set can shatter verisimilitude, which is another stated design goal.

In this balancing act between these two goals, I decided to use Encumbrance but in a simplified fashion: players need to list items by location and the character sheet needs to pass the smell test.

In other words, if a character is carrying two swords, a bow, three daggers, standard adventuring gear, and several bags of loot, the player needs to explain where all these are located and convincingly argue why the character doesn't suffer a penalty.

Literature Review: "Ill Met in Lankhmar" (1970)

Happy Holidays!

This week, in honor of Fritz Leiber's birthday on December 24th, I wanted to discuss one of the most famous stories by the man who literally coined the phrase "Swords & Sorcery", "Ill Met in Lankhmar":

Winner of both the Hugo and Nebula awards for Best Novella, "Ill Met in Lankhmar" is a prequel to more than thirty years of stories about the adventurous duo.  It is filled with Leiber's trademark twists and turns and shows off his economical yet witty style.  There's humor in his tongue-in-cheek tone and his world building is excellent, as the city of Lankhmar comes to life in these pages.

This ripping yarn  reveals "[t]he second and decisive meeting of Fafhrd and the Gray Mouser," two of the most famous figures in Swords & Sorcery.  One dark night, two members of the Thieves' Guild steal some valuable jewels but are, in turn, bushwhacked by a pair of independent operators, Fafhrd and the Grey Mouser.  After getting really drunk, the new soul mates (there's a clear bromance brewing) decide to behead Krovas, Grandmaster of the Thieves' Guild, at the behest of their girlfriends, despite Krovas being one of the most powerful mortals in the world.

Of course, it all goes horribly wrong.

I really wanted to like this story but I couldn't get past that we are meant to treat Fafhrd and the Gray Mouser as heroes, when they are not nice guys.  Setting aside that they are murderhobos (all they do in kill people and take their stuff), the adventurous duo exhibit some sociopathy in this story, including the murder of a helpless child.  Plus, there's the fact that Fafhrd is a deadbeat dad who abandoned his baby mama for some girl he randomly meets.

However, Leiber glosses all this over in the interest of presenting them positively.

Given Leiber's influence on the development of Dungeons & Dragons (see Appendix N of the AD&D Dungeon Master's Guide), another point that should have been in the story's favor is how much it reads like an RPG session.

Fafhrd and the Grey Mouser meet randomly when they are independently trying to rob the robbers.  There's no real reason why they should trust each other and form a party.  This is fine for an RPG but not so much for a story.

Further, there's the adventurous duo plan and disguises to infiltrate the Thieves' Guild.  Both are unbelievable and if there was any realism to "Ill Met in Lankhmar", Fafhrd and the Grey Mouser would have been immediately made, outed and executed.

If I was the DM, I would ask the players *REALLY* want to do this.  If they insisted, as an Old Schooler, I would let the dice fall where they may and then explain that the players need to roll up new characters.

RPG Design: Balancing Skills

This week, I wanted to discuss an important but sometimes underthought or overlooked issue for tabletop RPGs: Balancing Skills.  For purposes of this post, by "Balancing Skills," I'm referring to skills being balanced in terms of power/utility compared to each other.

In addition, by "Skills," I'm broadly referring to areas of a Player Character's expertise that can have an in-game effect.  This runs the gamut from swinging a sword to speaking a language to disarming a trap, etc.

You know, like nunchuck skills, bowhunting skills, computer hacking skills...

Every role-playing game has a skill system, whether or not it's expressly set forth in the rules set.  For example, in older editions of Dungeons & Dragons, skills are mostly subsumed into other parts of the rules (e.g., THAC0, ability scores, class features, etc.) or else hand waved and house ruled.  So, a PC's maximum number of languages and retainers are determined by Intelligence and Charisma, respectively.  Or, since there's no negotiation skill, the DM will often simply role-play a situation or ask the PC to make a roll against their Charisma score or some other target number (e.g., 1 in 6, 2 in 6, etc.).  It helps that D&D has a robust set of ability scores that, when doubled as skills, can cover many situations.

On the other hand, there are skill-based games such as GURPS, where the primary mechanic (success rolls) usually ends up as a skill check in actual play.  Unsurprisingly, skills usually take an outsized importance in classless games.  This is also often true in Stat + Skill systems, such as Exalted.

Problems arise when the designers to not think through their skill system.  Ideally, designers should consider both 1) Breadth and 2) Usage of skills so that a the value of a particular skill is roughly balanced against the others.

In terms of "Breadth," I'm referring to how broad is a particular skill's expertise.  For example, in Exalted, Melee covers proficiency in *ALL* weapons, making it an extremely broad skill.

By contrast, Call of Cthulhu divides up being sneaky into:

Conceal (Allows the visual covering up, secreting, or masking of an object or objects, perhaps with debris, cloth, or other intervening or illusion-promoting materials, perhaps by making a secret panel or false compartment, or perhaps by repainting or otherwise changing an item's characteristics to escape detection.)

Hide (As opposed to Conceal, Hide concerns the individual user's ability to escape detection in an unprepared position. Use this skill only in a pursuit situation, or when under surveillance or patrol.)

and

Sneak (The art of moving quietly, without alerting those who might hear. Used in combination with Hide, the investigator makes a single D100 roll, the result of which is matched against the investigator's percentages in both skills. Use this combination when silent movement is necessary.)

As a consequence, this division in CoC makes each individual skill weak and also makes it difficult to be a expert rogue.


A game's design should not only consider the general applicability of a skill, but also its Usage.  In terms of Usage, I'm referring to how often a skill is used in actual play.  Specific usage may vary due to genre or a group's play style, but usually some skills are used often and some skills are used rarely.

If a skill's Usage is relatively high, the designer should consider reducing it's Breadth.  Additionally, a game should have enough skills of sufficient Breadth to cover foreseeable situations of reasonable Usage.  So, for example, it's probably overkill for a typical fantasy game to include a skill for elephant riding.

In addition, the foregoing assumes that each skill costs the same number of skill points to purchase.  It's possible to balance by varying costs, using skill specialities, skill groups, etc.  However, as modern design tends toward greatly simplicity, I will stick with the assumption.


A notorious example of a game with a problematic skill system is Rifts:

There are over one hundred skills in Rifts, with gaps, overkill and redundancy.  Some are very narrow and not likely to ever be used in actual play (e.g., Boat Building).  Some skills should be combined (e.g., Automobile and Truck). Some skills overlap completely with another to make the other irrelevant (e.g., Concealment and Palming).

On the other hand, there's no Negotiation skill.

It doesn't help that there's no actual explanation of how to resolve non-combat skills.  The skills are rated by percentage, so presumably the player must make a d100 roll, but this is never expressly stated.